Aspirator assembly



Patented July 8, 1941 A UNITED STATES PATENT oFFicE mesne assignments, to Stator Corporation, a corporation of Rhode IslandA Application December 1, 1937,. Serial No, 177,489 s claims. l(o1. 23o-95) This invention relates to an improved aspirator arrangement, and more particularly to such an arrangement for use with' a relatively heavy propellant fluid such as mercury as, for example, in refrigerating systems employing mercury as a propellant. Y

aspirator".` assembly constructed in accordance with this invention; and

Fig. 2 is an elevational view of an. aspirator assembly, with parts shown in section.

My invention may be used in general in comi bination with aspirators, and particularly with In various aspirator installations, it is oftenv y desirable to arrange the outlet of the aspirator so that the outflowing fluid is diverted into Ya duct extending more or less at right angles to the outlet. For example, in a refrigerating system employing mercury as a propellant and employing an 'aqueous refrigerant, the aspirator may be provided with a funnel having a downward inclination from the propellant nozzle, and the outlet end of the funnel may be connected to an upwardly extending pipe. Since the funnel has a substantial length and since it is desirable to make such systems relatively compact, the funnel may be connected to such a pipe at a point fairly near the th-roat of the funnel.

Under such conditions I have found, particularly when a propellant such as mercury is employed, that the vapor particles may tend to wear away the wall of the pipe at the end of the aspirator funnel. Apparently, under certain conditions particles of mercury which didl not coalesce and condense in the funnel may havey sufcient velocity to afford a slight abrading elect. Accordingly the wall of the pipe may become seriously weakened. The present invention affords a simple arrangement to eliminate this disadvantage and to permit the compact installation of an aspirator with a vapor receiving duct extending at Aa relatively sharp angle to the outlet of the aspirator funnel.

To permit this desirable result, I preferably dispose material in the path of the particles at the juncture of the outlet and receiving pipe, which material is substantially immune to deterioration under the action of high velocity particles.

Further features of the invention relate to the arrangement of parts so that an adequate surface of liquid mercury can be provided to afford the desired protective results without requiring the use of an unduly large quantity of mercury and to permit the satisfactory structural arrangement of the parts of the system to maintain` the mercury pool at the desired'point.

In the accompanying drawing:

Fig. 1 is a diagrammatic view of an improved refrigerating system including an improved such aspirators employing, relatively heavy propell'ants such as mercury, but the invention is more particularly applicable to a refrigerating system which should be relatively compact, such aL systemr being diagram-matically disclosed in Fig.l 1l and being of the general typedisclosed. in United States Patent No. 1,761,551 to Eastman A. Weaver.

The system shown in. Fig., 1 comprises a boiler l provided with a heating element, such as an, electrical heater 2, and connected to the lower end of a riser pipe 3. Mercury vapor from the boiler I flows upwardly through the pipe 3 andv passes. through a nozzle 4 forming a portion of the aspirator assembly. This assembly also includes a mixing Ichamber l6 Whichis connected by avapor duct 1 to' an evaporator 8 containing a body of liquid refrigerant such as aqueous solution. Mercury vapor issues. from the nozzle 4 at high velocity and draws refrigerant vapor from the evaporator 8 through the duct 1. The mixed vapors flow into` a funnel 9' which preferably is inclined and whichis provided with cooling means such as fins l0. Mercury which has` condensed in, the funnel 9 passes from the outlet of the funnel. into the longer leg of a trap` I2 and the pumped vapor flows upwardly through a huid-receiving pipe i6 to acondenser I1. The lower end of the latter is connected to a refrigerant return duct I8 which provides a trap I9y containing a body of the heavy propellant.`

As liquid refrigerant piles up in the pipe I8,v a sumcient head is provided in that leg of the trap to permit the refrigerant tov bubble through the mercury and to return to the cooler 8. A trap'is connected to the bottom of the evaporator 8 to receive stray propellant therefrom and is connected by a pipe 22 to a mercury return pipe 23; the latter contains a column of mercury to balance vthe boiler pressure. The trap I'2 is also connected to the pipe 22 While the upper end of the pipe 23 is provided with a continuation V3.a toreceive condensed mercury from the mixing chamber 4.

Since the funnel 9 is preferably inclined at a moderate angle to the horizontal, e. g., at ananglev of the order of`1i5. degrees, and since the aspirator'assembly'may lee-relatively long, it may' be desirable lto have the receiving pipe I6 extend at an acute angle from its juncture with the outlet, as shown in Fig. 1.

In accordance with this invention, means is provided at the junction of the funnel and the receiving pipe to prevent the uid emitted from the funnel from undesirably abrading the metal wall of the system, as otherwise might occur were such means not provided.

Fig. 2 illustrates a funnel of the general character shown in Fig. 1, similar parts being idented by similar reference numerals, but this ligure shows in more detail the preferred arrangement of such a funnel. The aspirator assembly shown herein may include a funnel haV- ing a bore with inwardly tapered portions 28 and 29 land a throat 30, the funnel also haw'ng a flared outlet portion 3l. A funnel of this general form is more fully disclosed in the cepending application of Lyman F. Whitney, Serial No. 177,749, filed December 2, 1937. The pipe I6 extends at an acut-e angle to the outlet portion 3|, the latt-er being downwardly inclined and the adjoining receiving pipe section being substantially vertical.

In accordance with this invention, a small chamber 35 may be provided at the side of the pipe IB opposite the end of the funnel. This chamber may be `in the form of a short tubular section and may be pro-vided with a tapered portion 31 which decreases in diamet-er as it extends away from the pipe I6 and which terminates in a closed end 38. Thus the member 35 provides 'a tubular pocket which inclines downwardly from the juncture of the funnel outlet and the receiving pipe I6. This pocket may contain a body 4B of liquid mercury, the surface of this mercury obviously being horizontal and lying in such a lposition that particles of mercury which issue from the -outlet of the nozzle at high velocity may .impinge on the surface at an acute angle thereto, e. g., an an-gle of 15 degrees, thus having their kinetic energy absorbed. When the particles coming directly from the funnel pass into the liquid, their direction of movement is such that they may follow a relatively l-ong path in the liquid, although the pool is quite shallow.

Particles which are following paths abo-ve the surface of the mercury pool may strike the upper portion of t-he tapered section 31 and may thus be deflected so that they also strike the pool. Thus an arrangement is provided to avoid the direct movement of mercury particles infto contact with a surface at right angles to the path of vapor flow.

Fig. 2 also shows a preferred structural arrangement of the parts at-the end of the aspirator assembly, the tubular section 35 having a diameter which permits it to t over the outlet end 3l of the funnel lso that :these parts may be welded together. The pipe I'B is provided with two circular openings communicating respectively with the funnel and with the short tubular section 35. The pipe I6 extends throu-gh openings in the section 35 and these p-arts are welded to each other. The lower end of the pipe I6 has a tapered portion fitting wit-hin the flared end of the long leg of trap |72.

It is evident thai'l vapor particles issuing from the funnel 9 at low speed may readily turn with the rest of the vapor stream and ilow upwardly through pipe I6, but that particles which are still moving at high speed move across the lower end of pipe IB and eventually nd ,their way from the funnel 'and pass into the pocket.

into the pool 40, either directly impinging on the surface of this pool or striking the inclined upper surface of the tapered portion 31 and being `deflected into the pool. In either case, the energy of the particles is absorbed to a substantial degree by the liquid mercury. Since this liquid mercury does not Wear out, such an arrangement ao-rds a junction between the ducts of the system which is capable of lasting for an indenitely long period.

Should mercury be lost from the pocket 35 for Iany reason, the mercury pool is automatically replenished by mercury particles which issue On the other hand, the juncture between the pocket `35 and the pipe I6 alfords a spill-over so that excess mercury from the pool drains into the trap I2 and thence passes to the return pipe 23, Thus an arrangement is provided automatically to assure the maintenance of the mercury pool at the desired level to absorb the shock of high velocity particles, while permitting a relatively small amount of mercury to be employed for this purpose.

It should be understood that the present disclosure is for the purpose of illustration only and that this invention includes all modiiications and equivalents which fall within the scope of the appended claims.

I claim:

1. Aspirator assembly of the class described comprising a nozzle, a compression funnel having a downwardly extending outlet portion, a pipe extending at an angle to said portion to receive vapor therefrom, and a short tube terminating in a closed end, said tube being aligned with the outlet portion of the funnel, said tube having an inwardly tapered wall and forming a liquid-containing pocket, whereby particles leaving the outlet at high velocity either directly impinge on the liquid or are deflected by the wall to pass into the liquid.

2. Aspirator assembly of the class described comprising a nozzle, a compression funnel having a downwardly inclined outlet portion, a pipe extending at an angle to said portion to receive vapor therefrom, and a chamber disposed at the opposite side of the pipe from the outlet portion, said chamber having an inlet aligned with the outlet portion of the funnel and affording a shallow liquid-containing pocket, thereby to support a pool of liquid so that vapor particles which leave the outlet at high speed may strike the surface of the liquid at an angle thereto, and a drain having a spill-over connection with the tube toflimit the level of the pocketed liquid.

3. Method of absorbing the energy of high velocity iluid particles at the outlet of an aspirator which comprises directing some of the particles along substantially straight paths against the surface of a body of liquid and deflecting other particles against said surfaces by a surface at an acute angle to the surface of liquid.

. 4. Aspirator assembly of the class described comprising a compression funnel, a mixing chamber at the inlet of the funnel, a nozzle extending into the chamber to deliver mercury to the same, said funnel being provided with a throat spaced from the nozzle,v cooling means for the funnel, said funnel having an outlet portion, a Yvapor-receiving pipe connected to said outlet portion and extending at an angle thereto, a short tubular section having openings through which the pipe extends and having an end intertting with the end of the outlet portion, the wall of said pipe having opposite openings registering respectively with the outlet portion and the bore of the tubular section, the section having a closed end and affording means to absorb the shock of high velocity particles which do not pass directly from the outlet portion into the pipe.

5. Aspirator assembly of the class described comprising a nozzle, a compression funnel having a relatively straight outlet portion, a receiving pipe extending at an angle to said portion to receive vapor therefrom, and a shock absorbing means opposite said outlet, said means including a chamber containing a body of liquid whose upper surface meets a metal surface at an oblique angle, thereby providing mutually converging metal and liquid surfaces which high velocity particles may strike while moving at acute angles thereto, whereby the kinetic energy of the particles is absorbed.

6. Aspirator assembly of the class described comprising a nozzle, a compression funnel having an outlet portion, a pipe extending at an angle to the outlet of the funnel to receive vapor therefrom, and a tube disposed to receive high velocity particles Which do not pass along said pipe from said outlet, said tube affording a liquid-containing pocket, the tu-be having a wally positioned to deflect high velocity particles to cause them to pass into the liquid, and a drain having a spill-over connection with the tube to limit the level of the liquid in said pocket.

y RUSSELL A. GULICK. 

